Cooling apparatus for pluggable modules

ABSTRACT

A cooling apparatus for a pluggable module comprises a pluggable module cage to house the pluggable module and a heat pipe coupled with a hot interface at one end and a cold interface at another end. The cooling apparatus further comprises an attachment mechanism for attaching the hot interface and the heat pipe to the pluggable module. The attachment mechanism permits mobility required to insert and secure the pluggable module in place inside the pluggable module cage to allow a good thermal coupling between the hot interface and the pluggable module.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application hereby claims the benefit of and priority to U.S.Provisional Patent Application No. 62/255,761, titled “Cooling ApparatusFor Pluggable Modules”, filed on Nov. 16, 2015 and which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

The present disclosure relates to pluggable modules, specifically to acooling apparatus for pluggable modules.

Pluggable modules are commonly used in different applications, forexample the small form-factor pluggable (SFP), which is a compact,hot-pluggable transceiver used for both telecommunication and datacommunications applications. SFPs come in a variety of types. Althoughthe descriptions of the embodiments below refer to SFP transceivers asan example, the embodiments are applicable to any pluggable modules.

As known in the art, a heat sink is may be made of metal fins. Systemenclosures housing SFPs often use a forced air cooling mechanism (e.g.,fans) that circulate cool air through the fins to cool the SFPs insidethe enclosure. The amount of watts used by the SFP is limited by theability of this thermal management system to keep the SFP device belowits maximum operating temperature limit. The use of fans, which areactive parts, limits the reliability and durability of the system.

BRIEF SUMMARY OF THE INVENTION

A cooling apparatus for a pluggable module comprising a pluggable modulecage to house the pluggable module, and a heat pipe coupled with a hotinterface at one end and a cold interface at another end. The coolingapparatus further comprising an attachment mechanism for attaching thehot interface and the heat pipe to the pluggable module, wherein theattachment mechanism permits mobility required to insert and secure thepluggable module in place inside the pluggable module cage to allow agood thermal coupling between the hot interface and the pluggablemodule.

The foregoing and additional aspects and embodiments of the presentdisclosure will be apparent to those of ordinary skill in the art inview of the detailed description of various embodiments and/or aspects,which is made with reference to the drawings, a brief description ofwhich is provided next.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. It should be understood that this Summary is not intendedto identify key features or essential features of the claimed subjectmatter, nor is it intended to be used to limit the scope of the claimedsubject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosure can be better understood with referenceto the following drawings. While several implementations are describedin connection with these drawings, the disclosure is not limited to theimplementations disclosed herein. On the contrary, the intent is tocover all alternatives, modifications, and equivalents.

The foregoing and other advantages of the disclosure will becomeapparent upon reading the following detailed description and uponreference to the drawings.

FIG. 1 is an example of a pluggable module cage with a coolingapparatus.

FIG. 2 is an example of a heat pipe according to one implementation.

FIG. 3 is an example of a heat pipe according to one implementation.

While the present disclosure is susceptible to various modifications andalternative forms, specific embodiments or implementations have beenshown by way of example in the drawings and will be described in detailherein. It should be understood, however, that the disclosure is notintended to be limited to the particular forms disclosed. Rather, thedisclosure is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of an invention as defined by theappended claims.

DETAILED DESCRIPTION

An effect of the technology disclosed here in is the ability to coolSFPs without fans inside the system enclosure. Implementations of theinvention utilize heat pipes to cool SFPs.

A heat pipe is a heat-transfer device that combines the principles ofboth thermal conductivity and phase transition to efficiently manage thetransfer of heat between two solid interfaces.

At the hot interface of a heat pipe, a liquid in contact with athermally conductive solid surface turns into a vapor by absorbing heatfrom that surface. The vapor then travels along the heat pipe to thecold interface and condenses back into a liquid—releasing the latentheat. The liquid then returns to the hot interface through eithercapillary action, centrifugal force, or gravity, and the cycle repeats.Due to the very high heat transfer coefficients for boiling andcondensation, heat pipes are highly effective thermal conductors.

A system can be designed to contain in an enclosure one or more SFPs.SFPs are housed in a standard SFP cage, which is standardized byAmerican National Standard (ANSI) INF-8074i. SFP cages may include oneor more SFPs. Some SFP cages are designed to have a heat sink attachedto the top using a mobile attachment clipped to the cage that allowsproper insertion and tight coupling between the surface of thetransceiver and the heat sink. The description below assumes a singleSFP, but can be extended to a cage supporting several SFPs.

Referring to FIG. 1, in one embodiment, a heat pipe 102 is thermallycoupled with a hot interface or hot plate 106. The hot interface 106 isdesigned to be attached onto an SFP cage 101 using standard clips 104 orany other attachment mechanism that permits movement and mobilityrequired to insert and secure the SFP transceiver in place inside thecage and to provide a good thermal coupling between the hot interface106 and the SFP transceiver.

The transceiver inside an SFP cage 101 is thermally coupled with heatpipe 102. Heat pipe 102 is thermally coupled with a cold interface orcold plate 103, which can be attached or coupled to a system enclosure(not shown) or any other cooling mechanism. With this embodiment, thereis no need for fans to be used inside the system enclosure, thusincreasing the reliability and durability of the system. The hotinterface 106 is attached via the clip 104 or other similar attachmentapparatus to the SFP cage 101 so that hot interface 106 is thermallycoupled with the SFP transceiver. Clips 104 are flexible to allowmovement and mobility of the clips 104 to secure the SFP transceiver inplace inside the cage 101 and to provide a good thermal coupling betweenthe plate 106 and the SFP transceiver. In this manner, wherein the heatpipe is able to transfer heat of the SFP transceiver from the hot plateto the cold plate without a fan.

The heat pipe 102 can be of any shape to accommodate different designsand enclosures as long as it allows for the mobility required to insertand remove the SFP transceiver. For example, as shown in FIG. 2, theheat pipe 202 can be of a spring-like or coil shape that is mobilebetween the cold interface or cold plate 204 and the hot interface 206coupled with the SFP. Another example shown in FIG. 3 where the heatpipe 302 is of a bent shape allowing movement between the cold interfaceor cold plate 304 and the hot interface 306, which is attached to theSFP cage.

In another embodiment, the heat pipe can be affixed to the bottom sideof the SFP transceiver by having an opening in the printed circuit boardand in the SFP cage.

While particular implementations and applications of the presentdisclosure have been illustrated and described, it is to be understoodthat the present disclosure is not limited to the precise constructionand compositions disclosed herein and that various modifications,changes, and variations can be apparent from the foregoing descriptionswithout departing from the spirit and scope of an invention as definedin the appended claims.

What is claimed is:
 1. A cooling apparatus for a pluggable modulecomprising: a pluggable module cage to house the pluggable module; a hotplate; a cold plate; a heat pipe coupled to the hot plate at a first endof the heat pipe and to the cold plate at a second end of the heat pipe,the heat pipe configured to transfer heat from the hot plate to the coldplate; and an attachment mechanism configured to thermally couple thehot plate to the pluggable module.
 2. The cooling apparatus of claim 1wherein the pluggable module is a small form-factor pluggable (SFP)module.
 3. The cooling apparatus of claim 1 wherein the attachmentmechanism is a clip.
 4. The cooling apparatus of claim 1 wherein theattachment mechanism is further configured to couple the pluggablemodule to the pluggable module cage.
 5. The cooling apparatus of claim 1a non-linear portion configured to allow the heat pipe to flex.
 6. Thecooling apparatus of claim 5 wherein the non-linear portion comprises acoil shape.
 7. The cooling apparatus of claim 5 wherein the heat pipecomprises a bent shape.
 8. The cooling apparatus of claim 1 wherein theheat pipe is configured to transfer heat of the pluggable module fromthe hot plate to the cold plate without a fan.
 9. A fanless coolingsystem for a pluggable module comprising: a module cage configured tohouse the pluggable module; a heat pipe comprising a first portion, asecond portion, and a third portion between the first and secondportions; a hot plate thermally coupled to the first portion of the heatpipe; a cold plate thermally coupled to the second portion of the heatpipe; an attachment assembly configured to thermally couple the hotplate to the pluggable module; and wherein the heat pipe is configuredto transfer heat from the pluggable module from the hot plate to thecold plate.
 10. The fanless cooling system of claim 9 wherein the heatpipe is configured to transfer heat of the pluggable module from the hotplate to the cold plate without a fan.
 11. The fanless cooling system ofclaim 9 wherein the attachment assembly is further configured tostructurally couple the pluggable module to the pluggable module cage.12. The fanless cooling system of claim 9 wherein the third portion ofthe heat pipe is bent.
 13. The fanless cooling system of claim 9 whereinthe third portion of the heat pipe is non-linear.
 14. The fanlesscooling system of claim 9 wherein the third portion of the heat pipe isspring-shaped.
 15. The fanless cooling system of claim 9 wherein thethird portion of the heat pipe is configured to flex.
 16. The fanlesscooling system of claim 9 wherein the attachment assembly comprisesflexible clips.
 17. A method comprising; thermally coupling a first endof a heat pipe to a cold plate; thermally coupling a second end of aheat pipe to a hot plate; and thermally coupling the hot plate to apluggable module housed inside a pluggable module cage via an attachmentassembly, wherein the heat pipe is configured to transfer heat from thepluggable module from the hot plate to the cold plate.
 18. The method ofclaim 17 further comprising securing the pluggable module inside thepluggable module cage via the attachment assembly.
 19. The method ofclaim 18 wherein thermally coupling the hot plate to a pluggable modulecomprises thermally coupling the hot plate to a small form-factorpluggable transceiver.
 20. The method of claim 18 wherein the heat pipecomprises a non-linear portion configured to allow the heat pipe toflex.